Question: $\begin{aligned}&\phantom{{\times}}0\\ \\ &\underline{\times4}\\ \\ \end{aligned}$ $~~$
We can think of ${0} \times {4}$ as $0$ groups of $4$. Since there are $0$ groups, the answer is $0$. $\begin{aligned}&\phantom{{\times}}0\\ \\ &\underline{\times4}\\ \\ &\phantom{{\times}}0 \end{aligned}$